Learning Issues

1. What are the major disorders of the stifle joint?

Cranial and/or caudal cruciate ligament rupture,patella luxation, meniscal problems, collateral ligament injuries, and stifle luxation (excluding fractures)

2. What are the musculoskeletal disorders the Lab breed is predisposed to?

Hip dysplasia, hypertrophic osteodystrophy,osteochondritis dissecans, cranial cruciate rupture

3. What systemic diseases could cause/contribute to joint effusion and lameness?

Lymes disease, penetrating wound (of or near joint), infectious arthritis

4. What is significance of stiffness observed in hock joints on ambulation?

We read that lameness of the stifle is often accompanied by reduced motion in the hock - so lameness due to tearing of the cranial cruciate ligament could be responsible for the observed stiffness.

5. What are the range of values of cranial drawer that could be considered normal?

Cranial drawer signs of 0 - 2 mm can be normal.  Partial tears can be indicated by cranial drawer signs of 2 - 3 mm.  In young dogs it's normal to have cranial drawer signs of 4 - 5 mm, but you can feel the limit imposed by the intact ligament on palpation in that.

6. What besides collateral ligament rupture could cause medial instability of the stifle joint (and cause the observed valgus angulation of the left hind limb)?

The menisci contribute to the medial and lateral stablity of the stifle, so damage to the medial meniscus could cause medial instability.  Also, we're thinking that a torn caudal cruciate ligament could also cause medial instability.